Issues with removing form type names in Symfony 3.0.

Symfony3Forms.php

<?php

class ResourceAutocompleteType extends AbstractType
{
    // ...
    
    private $resourceName;
    
    public function __construct($resourceName)
    {
        $this->resourceName = $resourceName;
    }
    
    public function getName()
    {
        return sprintf('sylius_%s_autocomplete', $this->resourceName);
    }
}

// This allows us to generate form types:

// sylius_product_autocomplete
// sylius_customer_autocomplete

// Expected DX:

class MyCustomType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('products', 'sylius_product_autocomplete', array(
                'multiple' => true,
            ))
        ;
    }
}

// In Symfony 3.0 we would need to:

class ResourceAutocompleteType extends AbstractType
{
    // ...
    
    public function configureOptions(OptionsResolver $resolver)
    {
        $resolver->setRequired(array('resource')); // etc.
    }
    
    public function getName()
    {
        return 'sylius_resource_autocomplete';
    }
}

// Which results in following DX:

class MyCustomType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('products', 'sylius_resource_autocomplete', array(
                'resource' => 'sylius.product',
                'multiple' => true,
            ))
        ;
    }
}

/* This also affects other aspects of DX and our implementation:

    * We can no longer generate the form types based on configuration;
    * We cannot easily pass dependencies to specific form types;
    * Developer (end-user of the bundles/app) cannot override a specific form type easily:
    
    Right now can override ``sylius_product_autocomplete`` to change all autocompletes across whole app.
    With forms without type names, he would need to override all forms using ResourceAutocompleteType::class and replace it with his own class etc.

*/

Hi Pawel! Unfortunately auto-generation of form types was never an officially supported feature. With some shortening, your type could be adapted to:

class MyCustomType extends AbstractType
{
    public function buildForm(FormBuilderInterface $builder, array $options)
    {
        $builder
            ->add('products', AutocompleteType::class, array(
                'resource' => Product::class,
                'multiple' => true,
            ))
        ;
    }
}

This is pretty straight-forward and easy to use. Naming conflicts are now dealt with implicitly since you are importing the class name.

Developers can override your AutocompleteType entirely or add a type extension that is only activated if resource matches a certain class.

Dependencies should be passed in the DIC (as always).

@pjedrzejewski And what about using form type extensions to allow users to override Sylius form types? I think that is also the recommended way now to override form types in symfony 3.0. They live in a seperate service, and injecting stuff is easier, instead of altering the definition in a compiler pass.

@pjedrzejewski how can the container eventually resolve sprintf('sylius_%s_autocomplete', $this->resourceName) to sylius_product_autocomplete? There should be some extra configuration to handle that right? That same configuration (e.g. the Product::class) should in my opinion be handled via the options, as @webmozart mentions in https://gist.github.com/pjedrzejewski/a9d6728410040fc838fd#gistcomment-1647210